含甲巯咪唑杂环为端基的非环冠醚的合成

本文以甲巯咪唑杂环为新的端基,在相转移催化条件合成了五个开链冠醚,这些化合物均通过元素分析、UV、IR 、^1H和^13CNMR波谱鉴定.     

双羟甲基-18-冠-6及其衍生物的合成

报道了双羟甲基-18-冠-6及其正丁基、烯丙基、酯基、羧酸基衍生物的合成。所合成的八种新冠醚化合物的结构已经IR、MS、NMR、元素分析证实。     

非手性芳香冠醚同β-环糊精配位时所诱导出的圆二色性(ICD)研究

本文报道六种非手性芳香冠醚,即苯并-15-c-5,苯并-18-c-6,4-叔丁基苯并-15-c-5,二苯并-18-c-6,二苯并-24-c-8,4,4’二叔丁基二苯并-30-c-10,在3:2水-甲醇体系中同β-环糊精配位时的紫外光谱及诱导出的圆二色性谱。有趣的是,这些冠醚的邻苯二酚基生色团的~1A_1←~1A_1及~1B_2←~1A_1跃迁区的每一个谱带区均诱导出负正交替的圆二色性,经用Job连续变量法及摩尔比法确定系有两种配合物生成,一种是2:1 β-环糊精-冠醚配合物,另一种是1:2 β-环糊精-冠醚配合物。应用Shimizu等的理论结果,确定了含邻苯二酚基生色团的冠醚在β-环糊精空腔中的取向及其包结形态。就2:1配合物而言,本质上是一种亲脂相互作用,它遵循环糊精包结物的一般规律。对于1:2的β-环糊精-冠醚配合物,不存在β-环糊精空腔对冠醚的邻苯二酚基生色团的包结作用,所以推断其结构可能是,二个冠醚分子分别从β-环糊精圆筒的两端将环糊精分子包结起来,彼此间的作用是一种亲水相互作用。     

(苯并-15-冠-5)双Schiff 碱的合成

由苯并-15-冠-5经硝化、还原两步反应,制得4',5'-二氨基苯并-15-冠-5(2)。后者与水杨醛或其取代衍生物缩合,合成了一系列新的冠醚化双Schiff碱化合物1a～1h,经元素分析、IR、^1^HNMR和MS确证了其结构。     

高氯酸锂冠醚配合物的中红外光谱

测定了冠-4、冠-5、冠-6、冠-8等四种冠醚与高氯酸锂配位前后的中红外吸收光谱,观察到十种振动吸收峰在配位之后发生了变化.从水分子的配位状态、配位水吸收峰的锂同位素位移、冠醚骨架振动的变化、C=O吸收峰的分裂、苯环吸收峰的位移和Li~+与ClO_4~-的配位等方面对配合物的结构进行了分析和讨论.     

芳基重氮盐及其18-冠醚-6络合物的低频红外光谱

本文合成了九种不同取代基的苯基四氟硼酸重氮盐及其与18-冠醚-6形成的分子络合物, 考察它们的低频红外光谱, 讨论这类络合物的成键状况。     

稀土冠醚配合物的研究XV. 稀土硝酸盐与臂型冠醚配合物的合成 和性质研究

本工作以6-羟基-2,3,9,10-二苯并-1,4,8,11,14-五氧杂-环十六-2,9-二烯(1)及其衍生物(2,3和4)为配体,在乙腈中合成了十八种新的稀土硝酸盐配合物.其中羧酸冠醚4与稀土硝酸盐[Ln(NO_3)_3]分别形成2∶1型(Ln=La,Ce,Pr,Nd)、4∶3型(Ln=Sm)和3∶4型(Ln=Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y)配合物;冠醚1与La(NO_3)_3形成1∶1型配合物;冠醚2,3与La(NO_3)_3均形成2∶1型配合物.对所得配合物进行了元素分析、紫外光谱、红外光谱、~1H核磁共振、X射线光电子能谱等性质研究.对臂型冠醚中边臂的配位作用进行了初步讨论.     

席夫碱冠醚对铀酰离子萃取性能的研究

席无碱型大环配体对碱土、稀土及其它金属离子的显著配位作用早已受到广泛关注，已有不少相关报道。但是，利用席夫碱冠醚与金属离子的配位行为从溶液中萃取金属离子的研究却很少。本文研究了席夫碱冠醚（TBTDC）对铀酰离子的萃取行为。实验结果表明，TBTDC对铀酰离子有很好的萃取效果。     

大环聚醚化合物的合成研究(Ⅲ)——6-烷氧基二苯并-16-冠-5的合成

亲脂性强的冠醚化合物对金属离子选择性高、络合性能好,是高效率的相转移催化剂。对于二苯并型大环冠醚,在其芳环上引入烷基是增强冠醚脂溶性的一种有效途径;在其冠醚的脂环上引入烷氧基是提高冠醚脂溶性的又一方便的方法。为此,我们将开链冠醚(Ⅰ)与环氧氯丙烷反应得到6-羟基二苯并-16-冠-5(Ⅰ)。(Ⅱ)转化为钠盐。钠盐分别和硫酸二甲酯及7种卤代烃缩合成一组带有6-烷氧基的二苯并型冠醚化合物Ⅲ_(a—h)。反应为:     

含β-二酮的光致变色化合物的合成、结构表征及 其性能研究

合成了5种对羧基苯基重氮基β-二酮化合物,并与光致变色化合物相连,得到5种新型的多功能化合物。用元素分析、IR、^1HNMR和MS确定了其结构;研究了其紫外-可见光谱、荧光光谱及光致变色性;对化合物与Eu生成的配合物与DNA相互作用的性能进行了初步探讨,并对不同配体的配合物与DNA相互作用的情况进行了比较。     

The time-resolved spectra of a crowned indolinospiroben-zopyran

The photochromic process of an indolinospiropyran with a crown ether fragment (BN-BIPS) was studied by nanosecond laser photolysis technique. The results show that quinonic merocyanine B was formed via an excited singlet state from BN-BIPS; in acetonitrile solution, the transient absorption of merocyanine B showed an obvious decay while a new transient absorption at 440nm (from isomer C) was observed simultaneously. The decay of merocyanine B and the formation of isomer C (at 440nm) were accelerated in the presence of alkali metal cation. In contrast, the formation of isomer C was not observed in spiropyran without a crown ether fragment: BIPS.     

Synthesis and photochromism of spirobenzopyran derivatives bearing an oxymethylcrown ether moiety: metal ion-induced switching between positive and negative photochromisms

Spirobenzopyran derivatives carrying an oxymethylcrown ether moiety were synthesized, and their photochromism was studied in the presence of various metal ions in acetonitrile. The metal ion complexing ability of the crown ether moiety in crowned spirobenzopyrans affects both thermal isomerization and photoisomerization of their spirobenzopyran moiety to a great extent. When the interaction of the crown ether moiety with a metal ion was strong enough to cause thermal isomerization of the spirobenzopyran moiety to its corresponding merocyanine form and to suppress UV-induced isomerization to the merocyanine form, a negative photochromism appears. On the other hand, a relatively weak interaction of the crown ether moiety with a metal ion affords a positive photochromism. This phenomenon enables us to switch the photochromic behavior between positive and negative photochromisms.     

Synthesis of cyanine dyes derived from benzotellurazo‐15‐crown‐5

A series of crown ether cyanine dyes including crown ether styryl cyanine dyes, crown ether merocyanine dyes and crown ether squarylium cyanine dyes (unsymmetric and symmetric) derived from key intermediate 2‐methyl‐5,6(15‐crown‐5)benzotellurazole ( 1 ) were prepared.     

螺吡喃化合物在分析化学中的应用

螺吡喃作为一种有机光致变色化合物,能够发生无色闭环体螺吡喃与有色开环体部花菁之间可逆的结构异构化,由于具有特殊的分子识别能力和信号传导功能,已经成为分子探针领域极具吸引力的主体分子之一。螺吡喃不仅被广泛应用于光电材料领域作为分子器件,而且作为传感器广泛应用于分析化学领域。研究者们设计了多种具有不同结构的螺吡喃分子,将其应用于光化学和电化学传感领域。本文系统综述了螺吡喃化合物在分析化学领域的研究进展,包括螺吡喃作为光学探针在分子识别(对金属离子、阴离子及有机分子的定性及定量分析)方面的应用,以及螺吡喃在电化学免疫传感器中的应用。     

Negative photochromism of water-soluble pyridine-containing nitro-substituted spiropyrans

Negative photochromism of pyridine-containing nitro-substituted spiropyrans in solutions, solid phase, and polymer layers, as well as in complexes with terbium cations, has been studied by a spectral-kinetic method. It has been shown that the concentration of the merocyanine form and the efficiency of photochromic transformations depend on the length of the substituent at the nitrogen of the indoline moiety. A distinctive feature of the photochromic transformations of these compounds is slow spontaneous relaxation of the colorless photoinduced spiropyran form to the colored merocyanine form, which becomes practically acceptable only at a temperature of 80°C.     

Selective Acceleration of the Protonated Merocyanine‐Spiropyran Photochromic Transformation by Inclusion in Cucurbit[7]uril

The effect of cucurbit[7]uril (CB7) on the spiropyran‐merocyanine photochromic interconversion was studied in acidic and alkaline aqueous solutions. The merocyanine (MC) isomer was found to be the thermodynamically most stable form both in water and in the presence of CB7. A preferential binding of the protonated merocyanine (MCH⁺) to CB7 was observed with an equilibrium constant of 7.4 × 10⁴ m ^?1, and the complex formation led to significant diminution of acidity of the guest. The photoinduced transformation of MCH⁺ to the spiropyran isomer was accelerated 2.3‐fold upon addition of CB7, whereas the rates of the other photochromic processes were not affected. The partial inclusion of MCH⁺ in CB7 led to dual fluorescence due to the incomplete deprotonation in the singlet‐excited state.     

Synthesis of novel chalcone derivatives and their stabilization effect of spiropyran in PMMA films

Three novel bis-chalcone derivatives with different alkyldioxy spacers were synthesized and dispersed into polymethyl methacrylate(PMMA) chloroform solution with 6-nitro-1’-ethyl-3’,3’-dimethylspiro-2H-1-benzopyran-2,2’-indoline(ESP) to prepare photochromic PMMA films in a facile way.After irradiation with 365 nm UV light,the photocrosslinking reaction between chalcone units was proved to retard the dccolorization of merocyanine form of the photochromic spiropyran effectively,as results of the steric hindrance produced by photocycloaddition of chalcone groups.It has been found that the bis-chalcone molecule with the shortest spacer has the most effective stabilizing effect on retardation of decoloration of spiropyran.     

冠醚部花青的合成及其光电化学性能

部花青类化合物是一种光敏材料,由于它的结构比较稳定,吸收光谱范围可以调节以及容易做成薄膜电极等优点,用部花青染料做光伏器件的研究引起了人们的注视.Ghosh报道了用青类化合物做成高效率Schottky太阳能电池,光电转换效率达到1%.     

Crown-containing spironaphthoxazines and spiropyrans. 3. Synthesis and investigation of the merocyanine form of crown-containing spirobenzothiazolinonaphthoxazine

A method for the synthesis of the spirobenzothiazolinonaphthoxazine, stable in the merocyanine form and containing a crown-ether fragment was developed. The complexing properties of the prepared merocyanine compound and the spectroscopic and photochromic characteristics of its complexes with alkaline earth metal cations were studied by NMR and UV spectroscopy. The results were analyzed using quantum-chemical calculations. The addition of alkaline earth metal perchlorates to a solution of a crown ether-containing merocyanine dye in MeCN results in the coordination of metal cations to two binding centers, namely, the crown-ether fragment and the merocyanine oxygen atom. This gives rise to two types of complexes, which differ substantially in their structurally. The complexation induces changes in the UV spectra and influences on the photochromic behavior of the prepared compound.     

A semiclassical molecular dynamics of the photochromic ring-opening reaction of spiropyran

The photochromic ring-opening reaction of spiropyran(SP) has been investigated by a realistic semiclassical dynamics simulation,accompanied by SA3-CASSCF(12 10)/MS-CASPT2 potential energy curves(PECs) of S0–S2.The main simulation results show the dominate pathway corresponds to the ringopening process of trans-SP to form the most stable merocyanine(MC) product.These findings provide more important complementarity for interpreting experimental observations.